The advance is the latest step in a heated global race to establish a world standard for next-generation optical disks, which are expected to offer sharper images than current DVDs.
Toshiba said the new technology, developed jointly with Mitsubishi Kagaku Media Co. and Hayashibara Biochemical Laboratories Inc., can be used to manufacture single-recording HD-DVD disks with 15-gigabyte storage capacity.
Hitachi Maxell Ltd. and Mitsubishi Kagaku said they will market the new discs next spring, when Toshiba plans to launch high-definition DVD recorders.
Two technologies are competing to become the world standard in the battle for a high-definition successor to DVDs.
Toshiba leads a group that backs the HD-DVD format, while Sony Corp. leads a rival group promoting the Blu-ray Disc format.
Blu-ray has more capacity, with 50 gigabytes, compared to 30 gigabytes for HD-DVD read-only disks, but proponents of HD-DVD say their format is cheaper to make because the production method is similar to current DVDs.